Process for the production of dyestuffs for synthetic fibers



2,990,413 PROCESS FOR THE PRODUCTION OF DYE- STUFFS FOR SYNTHETIC FIBERSGiinter Gehrke, Leverkusen-Bayerwerk, Germany, assignor toFarbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, acorporation of Germany N Drawing. Filed Sept. 23, 1958, Ser. No. 762,678Claims priority, application Germany Mar. 7, 1955 5 Claims. (Cl.260-380) This invention relates to novel dyestuffs of the anthraquinoneseries.

It is an object of the present invention to provide novel dyestuffs ofthe anthraquinone series with good fastness properties. A further objectis to provide novel dyestufis for the dyeing of synthetic fibers with agood fastness to light and a good afiinity for said fibers. Stillanother object is to provide dyestuffs for the dyeing of polyesterfibers. Further objects will appear hereinafter.

These objects are attained in accordance with the present invention bytreating anthraquinona substituted in the four Ot-pOSltlOnS by amino andhydroxy groups such as the 4,8-diarnino-1,5-dihydroxy-,4,5-diamino-1,8-dihydroxy-, 5,8-diamino-1,4-dihydroxy-,4,5,8-triamino-l-hydroxyor 8-amino-l,4,5-trihydroxy anthraquinones withhalogenating agents. As halogenating agents there may be used halogenssuch as chlorine or bromine and halogenyielding compounds such assulfuryl chloride.

The process of the present invention may, for instance, be carried outby introducing the aforesaid anthraquinones into diluted or concentratedor slightly fuming sulfuric acid, into concentrated hydrohalic acid orinto inert organic solvents as, for example, haloor nitrobenzenes,glacial acetic acid or glycol monoethyl ether and by subsequently addinga halogen or halogenating compound such as sulfuryl chloride. It isexpedient to eifect the halogenation at a slightly elevated temperaturefor example at temperatures up to about 100 C. From the reaction mixturethe dyestulf formed can be obtained in known manner.

If necessary, boric acid and catalysts conventionally used inhalogenation such as iodine, may be added to the reaction mixture.Furthermore it is possible to carry out the halogenation stepwise,whereby also different halogens can be used for the halogenation.

In addition to 4,8-diamino-1,5-dihydroxyor4,5-diamino-l,8-dihydroxy-anthraquinone, there may also be used for theprocess according to the invention disulfonic acids of theseanthraquinones from which the two sulfoacid groups have been previouslysplit ofi by heating in sulfuric acid in the presence of reducingagents, in analogy to the process disclosed in German patentspecification No. 190,476. The subsequent halogenation may then beeffected in the same reaction mixture. The 5,8-diamino-1,4-dihydroxy-,4,5,8-tiiamino-l-hydroxyor S-amino-1,4,S-trihydroxy-anthraquinones canbe obtained from 1,4,5,8-tetrahydroxy or l,4,5,8-tetraaminoanthraquinones in which a corresponding number of hydroxy or aminogroups have been replaced respectively by amino or hydroxy groups. Insome cases mixtures are thus obtained which can be used according to theprocess of the present invention without necessity for isolation of thepure compounds. The processes for producing these compounds aredescribed in, for example, German patent specification Nos. 205,149,554,647, 556,459, 579,841, and 594,721.

The compounds obtained according to the present invention are dyestufi'sfor synthetic fibers, which are very fast to light. Whilst for examplethe unhalogenated 4,8-diamino-1,5-dihydroxyand the8-amino-1,4,5-trihydroxy anthraquinone have only a slight afiinity forsynthetic fibers, the dyestuffs produced according to the new Statesatent O 2,990,413 Patented June 27, 1 961 process by halogenation whichare mixtures of unhalogenated anthraquinones and anthraquinones with adifferent degree of halogenation-preferably monoand dihalogenatedanthraquinones which can contain also a minor amount of higherhalogenated anthraquinones-surprisingly possess in addition to a verygood fastness to light a good aflinity for the fibers. With increasinghalogen content the shade of the dyestufis obtained according to theinvention becomes more greenish and the fastness to subliming onpolyester fibers is improved, whilst the afiinity for the fibersdecreases again with increasing halogen content.

While dyestuffs with a bromine content of 540% or a chlorine content of3-25 can be used in principle for the dyeing of synthetic fibers, thedyestuffs have the best dyeing properties with an average halogencontent of about 0.75-1.25 atoms of the halogen based on theanthraquinones. If the halogen content is too high or too low thedyestufis lose their good properties. Dyestufis with an average halogencontent between.0.5l.5 mols based on the anthraquinones have suflicientsatisfying properties.

The novel dyestufis can be used for the dyeing of the various syntheticfibers by the methods usually applied for the dyeing of such fibers.Preferably, the dyestufis are used in finely devided dispersions underaddition of dispersing agents. Polyester fibers such as Dacron, Teryleneor Diolen can be dyed in the usual manner e.g. from a boiling dye bathwhich may contain, if desired, the usually applied carriers, or attemperatures of about C. under pressure.

Thus, strong blue dyeings of excellent fastness properties are obtained.Fibers of triacetyl cellulose such as Arnel, Courpleta or Tricel can bedyed by using the same methods. From a boiling dye bath on polyamidefibers such as Nylon or Perlon, dyeings of medium to strong shades areobtained with excellent fastness prop erties, while polyacrylonitrilefibers, e.g. Orlon or Dralon are dyed in pastel shades. Excellentdyeings are obtained as well by using copolyrners e.g. fromacrylonitrile and vinylchloride or vinylacetate or vinylidine chlorideand vinyl chloride such as Acrilan, Dynel or Saran.

This application is a continuation-in-part application of our copendingapplication Serial No. 568,161, filed February 28, 1956, now abandoned.

The following examples are given for the purpose of illustrating theinvention without in any way limiting it thereto, the parts being byweight.

Example 1 43 parts of 4,8-diamino-1,S-dihydroxy-anthraquinone-2,6-disulfonic acid (or the corresponding quantity of the sodium salt)are introduced into 500 parts of 96 percent sulfuric acid and 10 partsof boric acid and 25 parts of water are then added to the mixture. About3 parts of stannous chloride are added in small portions at 150 C. untilthe two sulfo groups are split oif and a sample fails to dissolve inaqueous pyridine. After the addition of 0.5 part of iodine, 30 parts ofbromine are run into the mixture of 50 C. and stirring is continued at50 C. until a sample contains 2830 percent of bromine. The mixture isthen put into ice water containing a little bisulfite solution, theprecipitate is filtered off by suction and washed until neutral. About38 parts of a dyestufi are thus obtained which dyes synthetic fibers inclear blue shades.

One part of this dyestuff is dispersed in 5000' parts of water andheated to 30-50 C. Thereafter 150 parts of a polyester fiber areintroduced and the temperature is raised within 20 minutes to C. Thedyeing is carried out at this temperature for one hour yielding a clearblue dyeing of excellent fastness properties. If the dyeing Example 2 27parts 'of 4,S-diamino-I,S-dihydroxy-anthraquinone and parts of boricacid are dissolved in 250 parts of sulfuric acid monohydrate and 0.1part of iodine and 10 parts of bromine are added thereto. The mixture isthen stirred at 50 C. until the bromine is used up. The reaction mixtureis then pressed onto ice, the precipitate is filtered off by suction andwashed neutral. 35 parts of a blue dyestufi are thus obtained whichcontains about percent of bromine.

With the dyestutf thus obtained triacetyl cellulose can be dyed byintroducing 150 parts of triacetyl cellulose into a dye bath consistingof one part of the dyestufi dispersed in the presence of a dispersingagent in 6000 parts of water at 40-50 C. The temperature is raisedwithin -40 minutes to 95-98 C. After dyeing for 1-2 hours at 95-98 C. aclear blue dyeing with excellent fastness properties is obtained. Ifdesired, a usually applied carrier can be added to'the dye bath.

When using only 7 parts of bromine, 32 parts of a dyestulf are obtainedwhich contains 18-20 percent of bromine and when using 5 parts ofbromine a dyestufi is obtained containing 13% of bromine.

By using this dyestufi in the manner described above for the dyeing oftriacetyl cellulose, dyeings with a slightly more reddish shade areobtained. In the same manner fibers of polyesters, polyamides andcopolymers can be dyed. By dyeing 150 parts of polyacrylonitrile fibersin the process described above with 0.2 part of the dyestuff, a lightblue dyeing with excellent fastness properties is obtained.

Similar dyestuffs are obtained when brominating 4,5-diamino-1,S-dihydroxy-anthraquinone instead of4,8-diamino-1,S-dihydroxy-anthraquinone.

Example 3 27 parts of 4,8-diamino-l,S-dihydroxy-anthraquinone, 7 partsof boric acid and 1 part of iodine are dissolved in 250 parts of a 92percent sulfuric acid. At 50C. chlorine is introduced into the solutionuntil a sample contains 20-21 percent of chlorine. After working upaccording to Example 1, 32 parts of a blue dyestufi are obtained.Similar dyestufis are obtained if such an amount of chlorine isintroduced that the dyestutfs obtained have a chlorine content of 6percent, 11 percent or 16 percent.

Example 5 27 parts of a 4,S-diamino-1,8-dihydroxy-anthraquinone areintroduced into 200 parts of nitrobenzene, 0.1 part of iodine is addedthereto and 33 parts of bromine are run 4 into the mixture at 50 C. Thewhole is stirred at 50 C. for a further 3 hours, the nitrobenzene isdriven off with steam, and a product is obtained containing about 37percent of bromine.

Example 6 27 parts of 4,8-diarnino-1,S-dihydroxy-anthraquinone aretreated in 200 parts of o-dichlorobenzene with 20 parts of sulfurylchloride. The mixture is stirred for an hour at 60 C. after coolingfiltered ofi by suction, and the residue is washed with methanol andwater. After drying, a dyestuft is obtained containing about 13 percentof chlorine.

Example 7 27.1 parts of 8-arnino-l,4,5-trihydroxy-anthraquinone producedaccording to the process of German patent specification No. 556,459 and13.5 parts of boric acid are dissolved in 270 parts of sulfuric acidmonohydrate, and 0.1 part of iodine and 20 parts of bromine are thenadded. The mixture is stirred at 50 C. until a tested sample shows acontent of about 20 percent of bromine. The reaction mixture is thenpoured onto ice. The precipitate formed is filtered ofi and washed tillneutral.

'A dye-bath is prepared by dispersing 1 part of the dyestuttin 3000parts of water. 100 parts of a polyester fiber are dyed from thisdye-bath for one hour at 120 C. under pressure. There is obtained astrong reddish blue dyeing having excellent fastness properties. It thedyeing is carried out under normal pressure at the boiling temperatureof the dye-bath a usual carrier has to be added such as benzoic acid orpor o-hydroxydiphenyl.

If the bromination of the anthraquinone is carried out with 30 parts ofbromine and if the mixture is worked up, if a tested sample shows acontent of 28-30 percent bromine, a dyestufi is obtained from which adyeing with a somewhat more greenish shade is obtained. If thebromination is carried out with only 10 parts of bromine and it thedyestuflfs obtained have a bromine content of 8-10% a somewhat morereddish dyestutt is obtained.

If the bromination is carried out in the same manner but using4,5,8-triamino-1-hydroxy-anthraquinone or 5,8-dihydroxy-1,4-diamino-anthraquinone of mixtures of these anthraquinonesclear blue dyestufis are obtained.

Instead of the polyester fibers there can be used also fibers ofpolyamides, polyvinylidinechloride, polyacrylonitrile or copolymerisatesof acrylonitrile and vinylacetate or copolymerisates obtained firomvinylidine chloride and vinylchloride.

Example 8 26.9 parts of 3,5,8-ttriamino-l-hydroxy-anthraquinone producedaccording to the process of German patent specification No. 594,721, and0.1 part of iodine are introduced into 200 parts of nitrobenzene. At atemperature of 50 C. 20 parts of bromine are added while stirring.Stirring is continued for another three hours at 60 C. Upon removing thenitrobenzene by steam distillation there are obtained 31 parts of adyestutr' containing about 25 percent of bromine.

One part of this dyestufi is dispersed in 6000 parts of water. From thisdye-bath parts of triacetylcellulose are dyed for 1 to 2 hours atboiling temperature. There is obtained a clear blue dyeing showingexcellent fastness properties. In the same manner there can be dyedfibers consisting of polyesters, polyamides or the copolymen'satesmentioned in Example 1. It 150 parts of polyacrylonitrile fibers aredyed from the dye-bath containing 0.2 part of the dyestufi, a light bluedyeing having excellent fastness properties, is obtained.

There is obtained a similar dyestufi it there are used instead of 20parts of bromine only 10 parts of bromine and subsequently 10 parts ofsulfuryl chloride.

Example 9 27 parts of 5,S-diamino-1,4-dihydroxy-anthraquinone producedaccording to the process of German patent specification No. 205,149 andparts of boric acid are dissolved in 250 parts of sulfuric acid (96%).Into this solution chlorine is introduced at 70 C. until a testedexample shows a content of 5-7% chlorine. The reaction mixture is thenpoured onto ice. The precipitate formed is filtered oil and washed tillneutral. A dyestufl is obtained which dyes polyester fibers in clearblue shades.

Example 10 27 parts of 5,8-diamino-1,4-dihydroxy anthraquinone aredissolved in 200 parts of o-dichlorobenzene and treated with 20 pants ofsulfuryl chloride. The mixture is heated slowly to 100 C. and stirredfor 1 hour at this temperature. The precipitate is filtered off andwashed with methanol and water. Thus a dyestufl is obtained containing1213% of chlorine.

If there are used 30 parts of sulfuryl chloride a dyestufi having achlorine content of about 17% is obtained.

Similar dyestufi is obtained if instead of the above anthraquinone thereis used 4,5,8-triamino-1-hydroxyanthraquinone. By using8-amino-1,4,5-trihydroxy-anthraquinone reddish blue dyestuif areobtained.

I claim:

1. An anthraquinone dyestufi mixture obtained by contacting ananthraquinone corresponding to the following formula Y 0 OH wherein oneY stands for NH and the other Y stands for OH, with a halogenating agentselected from the group consisting of chlorine, bromine and sulfm'ylchloride until the anthraquinone molecules contain an average halogencontent between 0.5 and 1.5 mols based on the anthraquinone.

2. The dyestufi mixture of claim 1 wherein the anthraqui-none is4,8-diamino-L5-dihydroxy anthraquinone.

3. The dyestufi mixture of claim 1 wherein the anthraquinone is4,5-diamino-1,8-dihydroxy anthraquinone.

4. An anthraqui-none dyestufi mixture of claim 1 wherein the halogencontent is bromine.

5. An anthraquinone dyestuff mixture of claim 1 wherein the halogencontent is chlorine.

References Cited in the file of this patent UNITED STATES PATENTS SpeckJuly 31, 1956 OTHER REFERENCES

1. AN ANTHRAQUINONE DYESTUFF MIXTURE OBTAINED BY CONTRACTING ANANTHRAQUINONE CORRESPONDING TO THE FOLLOWING FORMULA